INVESTIGATION IN THE CHROMONE SERIES. PART XIX. REACTION OF THE CHLORIDES OF CHROMONE-2- AND -3-CARBOXYLIC ACID WITH PHOSPHITES. PERKOW REACTION IN THE PRESENCE OF CONJUGATE DOUBLE BONDS

Abstract

4-Oxo-4H-1-benzopyran-3-carbonyl chloride forms in a Michaelis-Arbuzov reaction the corresponding α-ketophosphonate. As a result of further Michaelis-Arbuzov and Perkow reactions with tertiary phophites 4-oxo-4H-1-benzopyran-2-carbonyl chloride forms two stereoisomeric products (E) and (Z). The mechanism of their formation and the structure has been suggested on the basis of spectroscopic dates and reactions with proton nucleophilic reagents.

Key Words:

• Dimethyl (4-oxo-4H-1-benzopyran-3-yl)carbonylphosphonate
• (E) and (Z) 2(dialkylphosphato
• dialkylphosphono)methylene-4[(4-oxo-4H-1-benzopyran-2-yl)carbonyloxy]2H-1-benzopyran
• synthesis
• structure
• reaction mechanism